Device for producing a hardenable mass

ABSTRACT

The present invention relates to a device for producing a hardenable mass, preferably bone substitute and/or bone reinforcing material or bone cement or similar material. A mixing container may include a mixing space in which at least one powder and at least one liquid component are mixed to provide the hardenable mass. A piston may be provided in the mixing space of the mixing container. A screw device may be connectable to the mixing container such that the screw device may be configured to impart by screw movements a discharge movement to the piston to discharge the hardenable mass from the mixing space.

This is a division of application Ser. No. 12/585,194, filed Sep. 8,2009, which is a division of application Ser. No. 11/587,313, filed Oct.23, 2006, now U.S. Pat. No. 7,938,572, which is a 371 of PCT/SE05/00932,filed Jun. 17, 2005, which claims priority to Swedish patent applicationno. 0401604-4, filed Jun. 22, 2004.

FIELD

The present invention relates to a device for producing a hardenablemass, preferably a bone substitute and/or bone reinforcing material orbone cement or a similar material, wherein a mixing container has amixing space in which at least one powder and at least one liquidcomponent are mixed to provide the hardenable mass. A piston means isprovided in the mixing space of the mixing container, which piston meanscan be retained relative to the mixing container and be released suchthat it can move in relation thereto in a direction towards at least oneopening through which mixed mass can pass out of the mixing container,wherein at least one means which is rotatable relative to the mixingcontainer cooperates with the piston means for, in a retaining position,retaining said piston means relative to the mixing container and, byrotation to a release position, releasing the piston means such thatsaid piston means can move towards the opening.

Osteoporosis is rapidly increasing, particularly in the industrializedcountries. One reckons that about 50% of all women will suffer fromfractures due to osteoporosis. The major part of these fractures arefound on older people and lead to increased mortality, invalidity andhuge social costs. Vertebroplasty is a percutaneous injection of bonecement into a vertebra in order to alleviate pain in a compressionfracture caused by osteoporosis. Vertebroplasty was performed for thefirst time in France in 1984 and ten years later in the USA. Kyphoplastymeans balloon expansion in a collapsed vertebra for, if possible,reducing the risk for further collapse of the vertebra and provide acavity which is filled with bone cement. Kyphoplasty is regarded asexperimental in Europe, but has recently been approved by the FDA fortreatment of pathological fractures together with polymeric bonecements. The drawback with kyphoplasty is that this method requiresgeneral anaesthesia. Vertebroplasty however, can be performed in asurgery in fluoroscopy while administering sedatives and analgesics.Both methods give satisfactory pain relief in more than 75% of thecases. Early treatment of vertebra compression with vertebroplasty isstill discussed even if satisfactory pain relief can be provided. It isrecommended to wait at least six weeks before vertebroplasty isperformed. While waiting, pain killing treatment is tested. Earlytreatment with vertebroplasty however, can be considered if there is arisk for complications causing immobilization or if the pain is severe.A principal object with vertebroplasty is except pain relief to preventfurther collapse of vertebra. For identifying fractures, MR can be usedbesides common X-ray, said MR also showing oedema in the bone marrow andfracture gaps in the vertebra.

Vertebroplasty is performed with the patient lying on his or her stomachor on the side during intraveneous sedation and pain relief and undercontrol by a physician. During additional local anesthesia, a needle isinserted into a mandrine in the vertebra during fluoroscopy via atranspedicular or posteolateral inlet. The needle shall be positioned inthe centre line, preferably in the fore or anterior part of thevertebra. Then, injection of cement is carried through. Another needleis often necessary for symmetric filling of the vertebra. The injectionof cement is carefully supervised via TV-fluoroscopy and if leakageoccurs outside the limits of the vertebra, the injection is interrupted.The required volume for adequate pain relief is small, about 2-3 ml. Iflarger volumes are used, the risk increases that cement will leak out,as is the risk that bone marrow will spread into the circulation systemduring injection. The injection requires technical knowledge andtraining. Almost all substantial complications depend on leakage ofcement to the spinal canal or through the injection site. In more than20% there is an asymptomatic leakage of cement into paraspinal softparts or the lumbar venous system.

BACKGROUND

Devices for producing and discharging masses for the abovementioned andsimilar purposes are already known from U.S. Pat. No. 4,676,655, GB2239818, WO 2004/026377, WO 99/65597, EP 0657208 and WO 2004/002615.Prior art devices according to these publications however, are no simpledevices permitting simple handling in connection with vertebroplasty orsimilar.

SUMMARY

The object of the present invention is to provide a simple devicepermitting simple handling in connection with vertebroplasty andsimilar. This is arrived at by providing the device defined above withthe characterizing features of subsequent claim 1.

The significance of using a device permitting utterly simple handlingduring, inter alia, vertebroplasty and which relieves the surgeon fromseveral technical measures for moving cement from e.g. mixing in a bowlto a smaller syringe, is of the utmost importance. Simple handlingregarding mixing as well as discharge of cement, is important. Closedsystems are, if polymethylmethacrylate shall be used, necessary forhygienic reasons in order not to release monomer into the surroundingair. The possibility of having prepacked systems permittingsterilization together with closed transfer to smaller syringes forimproved control during injection, is obvious. Today, we have no simpleand efficient mixing and discharge equipment complying with thesedemands. The equipment must be able to manage mixing of polymeric aswell as ceramic materials in well-balanced volumes and to stop theinjection if leakage occurs. The invention comprises in this regard anumber of novelties.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be further described below with reference to theaccompanying drawings, in which:

FIG. 1 is a longitudinal section through the device according to theinvention during a mixing step;

FIG. 2 is an enlarged sectional view of a part of the device of FIG. 1and shows a mixing means interconnected with a discharge means;

FIG. 3 is a section through the device of FIG. 1 during a dischargestep;

FIG. 4 is a perspective view of a bracket forming part of the device ofFIG. 1;

FIG. 5 is a perspective view of a discharge piston forming part of thedevice of FIG. 1;

FIG. 6 is a perspective view of a rotary-movement preventing memberforming part of the device of FIG. 1;

FIG. 7 is a perspective view of a rotatable means forming part of thedevice of FIG. 1;

FIG. 8 is a side view of a screw mechanism for use at the device of FIG.1;

FIG. 9 illustrates a part of the device of FIG. 1 containing a powdercomponent and during injection of a liquid component;

FIG. 10 illustrates a part of the device of FIG. 1 connected to adistributor device;

FIG. 11 is a perspective view of the distributor device of FIG. 10; and

FIG. 12 illustrates the device of FIG. 1 during use in connection withvertebroplasty.

DETAILED DESCRIPTION

The device 1 illustrated in the drawings is adapted for producing ahardenable mass 2 such as bone substitute and/or bone reinforcingmaterial or bone cement or similar material. This mass 2 shall be fedand/or sucked out of the device 1 and comprises a mixing container 3 ofe.g. cylindrical shape. The mixing container 3 defines a mixing space 4in which at least one powder component 5 and at least one liquidcomponent 6 are mixed to produce the hardenable mass 2.

In the mixing space 4 there is provided a piston means 7 which isadapted to be retained relative to the mixing container 3 during amixing step and thereafter released such that it can move in the mixingspace 4 relative to the mixing container 3. In order to release thepiston means 7 there is provided a rotatable means 8 which in aretaining position P1 retains the piston means 7 relative to the mixingcontainer 3 and which by rotation from the retaining position P1 to arelease position P2 can be released relative to the mixing container 3,whereby the piston means 7 can move in the mixing space 4. The pistonmeans 7 and the rotatable means 8 are preferably directly or indirectlyinterconnected.

The device 1 preferably but not necessarily comprises a mixing means 9which is provided for mixing the powder and liquid components 5, 6 witheach other until the hardenable mass 2 has been produced. Then, the mass2 can be stirred with the mixing means 9 if this is appropriate ornecessary. The mixing means 9 may comprise an elongated member 10, e.g.a hollow or solid rod, which extends into the mixing space 4 and whichat an inner end within the mixing space 4 has a mixing disc 11 withaxial holes 12 passing through said disc. At an outer end outside themixing space 4, the elongated member 10 is provided with an operatinghandle 13 for operating the mixing means 9.

The mixing/stirring can be carried through in a known manner by movingthe mixing means 9 back and forth in the mixing space 4 and preferablyalso rotating it relative to said mixing space 4.

The piston means 7 preferably has an axial hole 14 extendingtherethrough and by means of which the elongated member 10 of the mixingmeans 9 extends into the mixing space 4. The elongated member 10cooperates with the piston means 7 through one or more sealing rings 15or similar, such that a sealing is provided between said members. Theelongated member 10 and the hole 14 of the piston means 7 are adapted toeach other such that said elongated member 10 can be moved and rotatedrelative to the piston means 7.

At least one outer sealing 16 or similar is provided on the piston means7 for cooperation with the inner side of the mixing container 3 suchthat a sealing is defined between the piston means 7 and said innerside. The outer sealing ring 16 is preferably designed such that itremoves mass 2 which deposits on the inner side of the mixing container3 when it moves in the mixing space 4.

The piston means 7 may also have an opening 17 with at least one filter18. The opening 17 is adapted to let out gases from the mixing space 4and the filter 18 is adapted to prevent the components 5 and/or 6 andthe mixed mass 2 from forcing its way out of the mixing space 4 throughthe opening 17.

A rotary-movement preventing member 19 is provided on the piston means7. This member 19 is annular and includes two axially provided hookportions 20, 21 which can be inserted into grooves 22, 23 in the pistonmeans 7 and hooked onto two shoulders 7 a, 7 b thereon in a radialdirection. By means of this positioning, the rotary-movement preventingmember 19 is attached to the piston means 7 and can not rotate relativeto said means.

The rotary-movement preventing member 19 further includes an axiallyprovided flange 24 which is adapted to cooperate with a bracket 25 inorder to prevent rotation of the rotary-movement preventing member 19and thus, the piston means 7, relative to the bracket 25 such that themixing means 9 is rotated relative to the piston means 7 for mixing ofthe powder and liquid components 5, 6. The bracket 25 has a cylindricalmember 27 with a hole 28 into which the rotatable means 8 can beinserted and through which said rotatable means can move when it is setin a release position P2. The cylindrical member 27 of the bracket 25may have an annular snap-in portion 29 which can be threaded into one ormore locking portions 30 which are located at the inner side of themixing container 3 and which allow the bracket 25 to be attached to themixing container 3 by a snap-in closure. Alternatively or in combinationwith said snap-in portion 29, the bracket 25 may have a number ofradially projecting members 33, 34 which can be attached to a radiallyoutwards directed flange 35 on the mixing container 3 by a snap-inclosure such that the bracket 25 can not rotate relative to saidcontainer.

The rotatable means 8 has a through hole 8 a through which the elongatedmember 10 of the mixing means 9 extends such that said elongated member10 is movable relative to the rotatable means 8 and vice versa.

The rotatable means 8 has a first flange 36 or a corresponding memberwhich in relation to the direction U extends radially outwards from therotatable means 8 towards a discharge opening 49 through which the mass2 shall pass out of the mixing container 3. Said first flange 36surrounds a part of the periphery of the rotatable means 8.

The hole 28 of the bracket 25 has a second flange 31 a or acorresponding second member which relative to the direction U isdirected radially into the hole 28. This second flange 31 a extendsalong a part of the periphery of the hole 28. A section 31 b or acorresponding third part of the hole 28 lacks said flange 31 a and isdesigned such that the first flange 36 of the rotatable means 8 can passtherethrough, whereby the entire rotatable means 8 can be brought topass through the hole 28 when the first flange 36 and the section 31 bcooperate.

When the rotatable means 8 is set in the retaining position P1 (FIG. 1),then the first and second flanges 36 and 31 a cooperate and prevent therotatable means 8 from moving relative to the bracket 25 in direction U,while the mixing means 9 can move and be brought to perform mixingmovements for mixing the powder and liquid components in the mixingspace 4.

The rotatable means 8 can be brought to its release position P2 (FIG. 2)by rotating it 180° relative to the bracket 25 from its retainingposition P1 and this rotary movement can be limited by bringing thefirst flange 36 thereof to engage or abut a rotary stop 32. Thereby, thefirst flange 36 of the rotary means 8 will be disengaged from thecooperation with the second flange 31 a of the bracket 25 and it caninstead cooperate with the section 31 b of the bracket 25 such that therotatable means 8 and thus, the piston means 7, can move and bedisplaced in direction U in relation thereto and thus, relative to themixing container 3.

The piston means 7 is prevented from rotating relative to the bracket 25by the flange 24 of the rotary-movement preventing member 19 engaging orgripping preferably into the section 31 b of the bracket 25 when therotatable means 8 retains the piston means 7 at the bracket 25.

The rotatable means 8 cooperates preferably with a coupling device 37which is provided to interconnect the piston means 7 and the elongatedmember 10 of the mixing means 9 such that the piston means 7 (and therotatable means 8 provided thereby) can be displaced in axial directionU relative to the mixing container 3 by means of the mixing means 9 fordischarge of mixed mass 2 from the mixing space 4. The coupling device37 is located between the rotatable means 8 and the piston means 7 andit is preferably provided to be operated by the rotatable means 8 suchthat it connects the piston means 7 to the elongated member 10 whilesimultaneously the rotatable means 8 is rotated from its retainingposition P1 to its release position P2. To this end, the coupling device37 may comprise a coupling means 38, e.g. a washer, which is threadedonto the elongated member 10 and which is located between the pistonmeans 7 and the rotatable means 8. The piston means 7 has a supportmember 39 which is axially directed towards the rotatable means 8 andlocated on one side of the elongated member 10, while there is a freespace 40 on the other side of the elongated member 10. The rotatablemeans 8 has an axially directed bore 41, the rear parts of which areprovided with a helical spring 42 or a similar resilient element and thefore parts with a pin 43 which projects out of the bore 41.

When the rotatable means 8 is set in its retaining position P1, the bore41 with the helical spring 42 is located on the same side of theelongated member 10 and the helical spring thereby presses the couplingmeans 38 against the support member 39 such that said coupling means 38is held in a neutral position P3 in which it is held against the supportmember 39 and permits displacement of the elongated member 10 of themixing means 9 in opposite axial mixing directions B, whereby the powderand liquid components 5, 6 can be mixed in the mixing space 4 with themixing means 9 while the piston means 7 is retained relative to themixing container 3.

When the rotatable means 8 is rotated 180° to its release position P2,the bore 41 and the helical spring 42 will also move 180° relative tothe support member 39 and the helical spring 42 will thereby press orpush the coupling means 38 into the space 40, which means that thecoupling means 38 is tilted relative to the elongated member 10 and isbrought to a coupling position P4 in which the coupling means 38 isfastened to the elongated member 10. Hereby, the piston means 7 isconnected to the mixing means 9 such that the piston means 7 can bedisplaced in the direction U by said mixing means 9.

Preferably, the coupling device 37 is designed such that it, after saidinterconnection of the mixing means 9 and the piston means 7, permitsrelease of the mixing means 9 relative to the piston means 7 if saidmixing means 9 is pulled in the return direction R relative to thepiston means 7.

On the operating handle 13 and/or on the elongated member 10 there maybe provided an outer member 45 with an open end portion 45 a and such acavity or depression 45 b within the end portion 45 a that said endportion will engage or abut the mixing container 3 when the mixing means9 is displaced in axial direction towards the mixing container 3 androtated relative to said container during mixing. Hereby, it isprevented that said rotation of the mixing means 9 is transferred to therotatable means 8.

The bracket 25 is preferably provided to prevent the piston means 7 andthe mixing means 9 from being pulled apart from the mixing container 3.

Since the rotatable means 8 can move together with the piston means 7 inthe mixing space 4 of the mixing container 3, it is ensured that thedevice 1 will be simple and that it provides for a simple and quickhandling when mixing of the powder and liquid components 5, 6 has beenperformed and the mixed mass 2 shall be discharged. To this end, it isonly necessary to rotate the rotatable means 8 from its retainingposition P1 to the release position P2, whereafter it is possible todisplace the piston means 7 by means of the mixing means 9 in thedirection U for discharge of the mass 2 from the mixing space 4.

As an alternative to the opening 17, at least one opening 47 can beprovided in the side of the mixing container 3 adjacent the piston means7 when said piston means is retained by the bracket 25. Since theopening 47 is located adjacent the piston means 7, it is closed when thepiston means 7 starts to move in the direction U and after furthermovement of the piston means 7, it will be located behind said pistonmeans, which means that only gas and no mass 2 can be pressed outthrough the opening 47.

As an alternative to said openings, there may be at least one opening 48in the side of the mixing container 3 about half the way between thepiston means 7, when retained by the bracket 25, and a discharge opening49 which is provided in the mixing container 3 for discharge of the mass2 from said container. The opening 48 may be closable when necessary.

The abovementioned opening 17 or openings 47 or 48 permit gas to bepressed out of the mixing space 4 when e.g. the liquid component 6 isinjected into said space. Since gas hereby can be pressed out, injectionof the liquid component 6 is facilitated. Due to its location, theopening 48 permits gas which is entrapped in the mass 2 to be pressedout of or escape from said mass during discharge thereof.

At least one vacuum generating device can be provided to generate avacuum in the mixing space 4 for various purposes, preferably forfacilitating quick suction of the liquid component 6 to and distributionthereof in the powder component 5 and/or e.g. for sucking out toxicgases therefrom, which are generated during mixing of the powder andliquid components 5, 6. In this case, there may be no openings which letair into the mixing container 3, but said container must be sealed.

In order to generate a vacuum in the mixing space 4 for e.g. sucking outtoxic gases, there may be a first vacuum generating device 50 which at asuitable location can be connected to the mixing container 3. Such afirst vacuum generating device 50 is schematically illustrated in FIG.1.

For discharge, the mixing means 9 can be subjected to linear forces suchthat said mixing means 9 and the piston means 7 are displaced linearlyrelative to the mixing container 3. Alternatively, the mixing means 9can be displaced linearly by influence from a screw device 51.

The screw device 51 e.g. includes a nut-like member 52 which has alaterally open fork-like member 52 a with laterally open grooves 53permitting sideways threading of the nut-like member 52 onto the flange35 of the mixing container 3 such that said member 52 is stuck on themixing container 3.

The nut-like member 52 is provided with a tapped hole 54 for ascrew-like member 55 with outer threads 56 which mesh with the threadsin the tapped hole 54 of the nut-like member 52. The screw-like member55 may be a pipe member with a multi-side nut 58 and the pipe member mayhave a longitudinal slit 57 which is open in a lateral direction and thenut may have an open side 60 such that the screw-like member 55 and thenut 58 can be threaded onto the elongated member 10 of the mixing means9. The nut 58 is adapted to fit into a corresponding multi-side hole 59in the outer member 45 or any other member on or of the operating handle13.

Due to the abovementioned embodiment of the screw device 51, said devicecan be non-rotatably located on the mixing container 3 and since the nut58 can be inserted into the hole 59, the screw-like member 55 may, bymeans of the operating handle 13, be screwed into the nut-like member 52via e.g. the outer member 45, whereby the end portion 61 of thescrew-like member 55 is brought in contact with the rotatable means 8and can impart dis-charge forces in the direction U to the rotatablemeans 8 and through said rotatable means to the piston means 7.

The piston means 7 can be moved in the direction U either by manuallypressing the operating handle 13 or rotating it and transfer the rotarymovement by means of the screw device 51. If great forces are requiredfor discharging the mass 2 from the mixing space 4, one can use agun-like discharge device 62 or a similar device as is schematicallyindicated in FIG. 1. The mixing container 3 is positioned therein suchthat a pressure means 63 can cooperate with the mixing means 9 ordirectly with the piston means 7 if there is no mixing means. Thepressure means 63 is operated by a manually depressable trigger whichcan move the pressure means 63 stepwise such that said pressure meanswith force press the mixing means 9 and/or the piston means 7 forward inthe direction U.

As is apparent from FIG. 9, the mixing space 4 of the mixing container 3may carry the powder component 5 when the device 1 is delivered. Thedischarge opening 49 is hereby closed by a closing device 64 whichprevents the powder component 5 from falling out of the mixing space 4.

The liquid component 6 can be provided in a liquid container 65 and canbe fed into the mixing space 4 for mixing therein with the powdercomponent 5.

The liquid container 65 has a discharge end 66 and the closing device 64can be designed such that the discharge end 66 can open the closingdevice 64 when it is inserted into said device for injecting the liquidcomponent 6 into the mixing space 4 and the powder component 5 therein.To this end, the closing device 64 may comprise a valve body 64 a whichis normally closed and which is opened by the discharge end 66 when saidend is inserted into the closing device 64 and automatically returned toclosed position when the discharge end 66 is removed or withdrawn fromthe closing device 64.

A valve 67 can be provided to cooperate with the closing device 64 topermit gas to escape from the mixing space 4 when the liquid component 6is injected into said space from the liquid container 65. This valve 67can be closed and may be opened when required.

In order to vibrate the content of the mixing space 4, i.e. the powderand liquid components 5, 6 and/or the mass 2, the mixing container 3 orparts thereof may be brought in contact with a vibrating device 68schematically illustrated in FIG. 9.

As is apparent from FIG. 10, the mixing container 3 can be connected toa distributor device 69 or vice versa. Several containers 70 can beconnected thereto or vice versa, such that mass 2 mixed in the mixingspace 4 can be fed out or discharged from said mixing space and into thedistributor device 69. The distributor device 69 distributes the mass 2to the various containers 70 such that portions of the mass 2 are fedinto inner spaces 71 in the containers 70. The inner space 71 in eachcontainer 70 is substantially smaller than the mixing space 4 of themixing container 3, which means that one can fill the spaces 71 of aplurality of containers 70, e.g. the spaces 71 of eight containers 70,with a part volume 2 a of the mass 2 from the mixing space 4.

When the spaces 71 of the respective number of containers 70 are filledwith said part volume 2 a of the mass 2, each container 70 can beremoved from the distributor device 69 or vice versa and the part volume2 a of mass 2 in the container 70 can be fed and/or sucked out of thecontainer 70.

The distributor device 69 preferably comprises a distributor body 72with an axial inlet pipe 73 which can be located close to such an outletor discharge end 74 of the mixing container 3 having the dischargeopening 49. The inlet pipe 73 can be located at the discharge end 74 byscrewing on or in any other suitable manner such that inner passages inthe distributor body 72 communicate with the discharge opening 49. Ofcourse, the mixing container may instead be located on the inlet pipe73.

The distributor device 69 may also comprise a number of discharge pipes75-82, at least two and e.g. eight pipes, which extend radially in astar-like manner from the distributor body 72 and which communicate withinner members of the distributor body 72.

Each container 70 has a front part 84 through which it can be mounted,e.g. screwed on to one of the discharge pipes 75-82 of the distributordevice 69 or vice versa, such that a part volume 2 a of mass 2 can befed into the space 71. During this filling of the space 71, a piston 86forming part of the container 70 is preferably located in a rear part 85of the container 70. After the space 71 has been filled with the partvolume 2 a of mass 2, a cannula or needle 83 can be located on the frontpart 84. The part volume 2 a of mass 2 is fed or sucked out of the space71 of the container 70 through said cannula 83.

Each container 70 may eventually have an opening 87 which preferably isfound in the rear part 85 and immediately in front of the piston 86 whensaid piston is situated in the rear part 85. This opening 87 allows gasin the space 71 of the container 70 to be pressed out of the space whensaid part volume 2 a of mass 2 is fed into said space 71. Hereby, it isprevented that gas in the space 71 resists entrance of the part volume 2a of mass 2 into said space 71. The opening 87 has e.g. a diameter of0.2-1.0 mm, preferably about 0.6 mm.

The opening 87 may alternatively be a groove (not shown) providedaxially in the inner side of the container 70 and extending beyond thepiston 86 when said piston is situated in the rear part 85 of thecontainer 70.

When the required number of containers 70 have been filled with the partvolume 2 a of mass 2, one container 70 at the time is removed from thedistributor device 69 and a cannula or needle 83 is mounted preferablyon the front part 84 of the container 70 such that the part volume 2 aof mass 2 can be fed or sucked out through the cannula 83 with orwithout support from the piston 86 until the space 71 is empty. Byremoving one container 70 at the time from the distributor device 69 andletting the other filled containers 70 remain mounted thereon, it isachieved that the mass 2 in the containers 70 not yet removed is notsubjected to atmospheric air for an unnecessarily long time.

Since the size of the space 71 in each container 70 is known, one knowsexactly how large a part volume 2 a of mass 2 which is fed out of ordischarged from each container 70. For treating spongy bone 89 with mass2, said mass 2 can be sucked into inner parts 89 a of the spongy bone89. To this end, a container 70 is connected to the spongy bone 89 byinserting the cannula 83 thereof, or a member (not shown) to which thecannula 83 can be connected, into the inner parts 89 a such that thespace 71 of the container 70 communicates therewith. To said inner parts89 a of the spongy bone 89 there is also connected at least one vacuumsource 90 through a connection line 92 for generating a vacuum in theinner parts 89 a and in the space 71 of the container 70 connectedthereto such that the part volume 2 a of mass 2 is sucked out of saidspace 71 and through the cannula 83 into the inner parts 89 a of thespongy bone 89. During this suction step, the piston 86 may eventuallybe displaced in the direction U for supporting the suction of the partvolume 2 a of the mass 2 out of the space 71.

Inner parts 89 a of the spongy bone 89 can be provided with mass 2 fromthe mixing container 3. The mixing container 3 can be provided with acannula or needle (not shown) or similar and this cannula is insertedinto the inner parts 89 a. The mass 2 can thereby be sucked out of themixing space 4 of the mixing container 3 and into the inner parts 89 aby means of the vacuum source 90. Eventually, this suction of mass 2from the mixing space 4 may be supported by a displacement of the pistonmeans 7 in the direction U.

The spongy bone 89 may e.g. be a spongy vertebra or an osteoporosisfracture in the form of a thighbone (femoral) or knee (patellar)fracture.

Mixed mass 2 in the mixing container 3 can be used for fixation ofimplants, whereby one can provide the container with a discharge pipe orsimilar (not shown), through which the mass 2 is discharged by means ofthe piston means 7 into cavities in the bone in which the implant shallbe fixed.

The mass 2 may consist of bone substitute and/or bone reinforcingmaterial which primarily consist of calcium base material or ceramicswhich can be mixed with a hardener, e.g. water. These substances may beselected from the group comprising calcium sulphate-α-hemihydrate,calcium sulphate-β-hemihydrate, calcium sulphate-dihydrate, calciumcarbonate, α-tricalcium phosphate, hydroxyapatite, dicalciumphosphate-dihydrate, anhydrous dicalcium phosphate, tetracalciumphosphate, β-tricalcium phosphate, calcium deficient hydroxyapatite,monocalcium phosphate-monohydrate, monocalcium phosphate,calcium-pyurophosphate, precipitated hydroxyapatite, carbonaceousapatite (dahlite), octacalcium phosphate, amorphous calcium phosphate,oxyapatite, carbonato apatite and calcium aluminate.

A ceramic material may be calcium aluminate, which forms part of theproduct Doxa T from the company Doxa (www.doxa.se/pdf/nyhet_(—)1.pdf).

X-ray contrast agents can be added to said ceramic bone substituteand/or bone reinforcing material, e.g. water soluble non-ionic X-raycontrast agents selected from the group comprising iohexol, ioversol,iopamidol, iotrolan, metrizamide, iodecimol, ioglucol, ioglucamide,ioglunide, iogulamide, iomeprol, iopentol, iopromide, iosarcol,iosimide, iotusal, ioxilan, iofrotal and iodecol.

Alternatively, the mass 2 can be a hardenable bone cement comprisingpolymer and monomer components. The polymer may bepolymethylmethacrylate (PMMA) and the monomer methyl methacrylate (MMA).A polymer base material can be the product Cortoss™ from the companyOrthovita in the U.S.A. For composition seewww.orthovita.com/products/cortoss/oustechspecs.html. Another polymerbase material can be the product SECOUR® Acrylic Resin PMMA fromparallax medical Inc.(www.parallax-medical.com/go/91-92b550-5642_-1157-a432-d7a2b98310fe).

The mass 2 can be a bone substitute and/or bone reinforcing material andconsist of a mineral and/or a ceramic in combination with polymermaterial.

The screw device 51 may be a device which can be connected to a mixingcontainer 3 which is designed in another way than what is illustrated inthe drawings and where the piston means 7 is located and operated inanother way than what is shown in the drawings.

The distributor device 69 can be connected to a mixing container 3 orvice versa which is designed in another way than what is shown in thedrawings and where the piston means 7 is mounted in another way thanwhat is shown in the drawings.

The invention is not limited to the embodiments described above andillustrated in the drawings. As examples not described in detail, itshould be mentioned that the mass 2 may be another type of mass thanbone substitute and/or bone reinforcing material or bone cement orsimilar. The rotatable means 8 may cooperate with the piston means withother means than those shown and described; mixing may be carriedthrough in another way than with a mixing means 9 and if there is such ameans, this may be designed otherwise; the mixing container 3 may bedesigned in another way than what is described and illustrated; whenusing a screw device 51, this may be of another type than the onedescribed and illustrated and this also refers to the distributor device69. The piston means 7 may either be moved in the direction U by themixing means 9 or be sucked in the same direction by the vacuum source90, but it is also possible to move the piston means 7 by using themixing means 9 and the vacuum source 90 simultaneously. The device 1 maybe of the disposable type or used repeatedly.

1-56. (canceled)
 57. A screw device, the screw device comprising: thescrew device connectable to a mixing container of an apparatus forproducing a hardenable mass, the mixing container having a mixing spaceand a mixer to mix at least one powder and at least one liquid componentto produce the hardenable mass, wherein a piston arranged in the mixingspace is provided to discharge the hardenable mass from the mixingspace, wherein the screw device is connectable to the mixing containersuch that the screw device is configured to impart by screw movements adischarge movement to the piston to discharge the hardenable mass fromthe mixing space.
 58. The screw device according to claim 57, whereinthe screw device comprises a first member that is non-rotatablyconnectable to the mixing container, and wherein the screw devicefurther includes a second member configured to be screwed into the firstmember so as to move the piston by screwing the second member into thefirst member.
 59. The screw device according to claim 58, wherein thefirst member is a nut, and the second member is a screw.
 60. The screwdevice according to claim 58, wherein the second member is adapted toengage a part of the mixer of the mixing container, such that the secondmember linearly displaces the mixer when the second member is screwedinto the first member.
 61. The screw device according to claim 60,wherein the second member is connectable to the part of the mixer. 62.The screw device according to claim 61, wherein the part of the mixer isan operating handle of the mixer.
 63. The screw device according toclaim 61, wherein the second member is a pipe member with a multi-sidednut; wherein the pipe member has a longitudinal slit which is open in alateral direction; and wherein the nut has an open side such that thepipe member and the nut are configured to be threaded onto an elongatedmember of the mixing means.
 64. The screw device according to claim 62,wherein the second member is a pipe member with a multi-sided nut;wherein the pipe member has a longitudinal slit which is open in alateral direction; and wherein the nut has an open side such that thepipe member and the nut are configured to be threaded onto an elongatedmember of the mixing means.
 65. A mixing system for producing anddischarging a hardenable mass, the system comprising: a mixing containerhaving a mixing space, a mixer to mix at least one powder and at leastone liquid component in the mixing space to produce the hardenable mass,a piston arranged in the mixing space for discharging the hardenablemass from the mixing space, and a screw device connectable to the mixingcontainer such that the screw device is configured to impart by screwmovements a discharge movement to the piston for discharging thehardenable mass from the mixing space.
 66. The mixing system accordingto claim 65, wherein the screw device comprises a first member that isnon-rotatably connectable to the mixing container, and wherein the screwdevice further includes a second member that is configured to be screwedinto the first member so as to move the piston by screwing the secondmember into the first member.
 67. The mixing system of claim 66, whereinthe first member is a nut-like member, and the second member is ascrew-like member.
 68. The mixing system according to claim 66, whereinthe second member is adapted to engage at least a part of the mixer,such that the second member linearly displaces the mixer when the secondmember is screwed into the first member.
 69. The mixing system accordingto claim 68, wherein the second member is connectable to the part of themixer.
 70. The mixing system according to claim 69, wherein the mixerincludes an operating handle.
 71. The mixing system according to claim66, wherein the mixer comprises an elongated member; wherein the secondmember is a pipe member with a multi-sided nut; wherein the pipe memberhas a longitudinal slit that is open in a lateral direction; and whereinthe nut has an open side such that the pipe member and the nut areconfigured to be threaded onto the elongated member of the mixer. 72.The mixing system according to claim 68, wherein the mixer comprises anelongated member; wherein the second member is a pipe member with amulti-sided nut; wherein the pipe member has a longitudinal slit that isopen in a lateral direction; and wherein the nut has an open side suchthat the pipe member and the nut are configured to be threaded onto theelongated member of the mixer.
 73. The mixing system according to claim66, wherein the first member comprises a fork member that is connectableto a flange of the mixing container.
 74. The mixing system according toclaim 68, wherein the first member comprises a fork member that isconnectable to a flange of the mixing container.
 75. A method ofdischarging a hardenable mass produced in a mixing container, the mixingcontainer having a mixing space for mixing at least one powder and atleast one liquid component to produce the hardenable mass, and themixing container having arranged in the mixing space a piston todischarge the hardenable mass from the mixing space, comprising:connecting a screw device to the mixing container; imparting by screwmovements a discharge movement to the piston to discharge the hardenablemass from the mixing space.
 76. A method according to claim 75, whereinthe screw device includes a first member and a second member, whereinconnecting comprises non-rotatably connecting the first member to themixing container, and wherein imparting a discharge movement comprisesscrewing the second member into the first member so as to displace thepiston and a mixer.
 77. A method according to claim 75, wherein thehardenable mass is a material chosen from a bone substitute material, abone reinforcing material, and a bone cement.
 78. A method according toclaim 76, wherein the hardenable mass is a material chosen from a bonesubstitute material, a bone reinforcing material, and a bone cement.